Step 1) Find the square root of the area or find the side length of the square
Step 2) Find the distance of the 2 adjacent sides
Step 3) Figure out how long it takes to walk the two adjacent sides
Step 4) Find out how long it takes to walk diagonally
Subtract the time it takes to walk diagonally from the time it takes to walk the 2 sides.
42.25 - 29.85 = 12.4 seconds.
Laura saves 12.4 seconds by walking diagonally instead of walking the two adjacent sides.